Module contributed by Matteo Ghetta - funded by Scuola Superiore Sant’Anna
Processing allows a lot of different input and output parameter that can be used in the script body. Here a summary table:
Parameter | Syntax example | Returning objects |
---|---|---|
vector | Layer = vector | SpatialDataFrame object, default object of rgdal package |
vector point | Layer = vector point | SpatialPointDataFrame object, default object of rgdal package |
vector line | Layer = vector line | SpatialLineDataFrame object, default object of rgdal package |
vector polygon | Layer = vector polygon | SpatialPolygonsDataFrame object, default object of rgdal package |
multiple vector | Layer = multiple vector | SpatialDataFrame objects, default object of rgdal package |
table | Layer = table | dataframe conversion from csv, default object of read.csv function |
field | Field = Field Layer | name of the Field selected, e.g. "Area" |
raster | Layer = raster | RasterBrick object, default object of raster package |
multiple raster | Layer = multiple raster | RasterBrick objects, default object of raster package |
number | N = number | integer or floating number chosen |
string | S = string | string added in the box |
longstring | LS = longstring | string added in the box, could be longer then the normal string |
selection | S = selection first;second;third | string of the selected item chosen in the dropdown menu |
crs | C = crs | string of the resulting CRS chosen, in the format: "EPGS:4326" |
extent | E = extent | Extent object of the raster package, you can extract values as E@xmin |
point | P = point | when clicked on the map, you have the coordinates of the point |
file | F = file | path of the file chosen, e.g. “/home/matteo/file.txt” |
folder | F = folder | path of the folder chosen, e.g. “/home/matteo/Downloads” |
Any of the input could be also OPTIONAL, that means that you have a handy way to tell the script to ignore this parameter.
In order to set an input as optional, you just have to add the string optional before the input, e.g:
##Layer = vector
##Field1 = Field Layer
##Field2 = optional Field Layer
Output parameters take the Input names you gave at the beginning of the script and write the object you want.
Parameter | Syntax example |
---|---|
vector | Output = output vector |
raster | Output = output raster |
table | Output = output table |
file | Output = output file |
Poznámka
for the plot input type, you can save the plot as png directly from the Processing Result Viewer or you can choose to save the plot directly from the algorithm interface.
In order to better understand all the input and output parameters, please have a look at the R Syntax chapter.